ABSTRACT
BACKGROUND: Hematopoietic progenitor kinase 1 (HPK1 or MAP4K1) has been demonstrated as a negative intracellular immune checkpoint in mediating antitumor immunity in studies with HPK1 knockout and kinase dead mice. Pharmacological inhibition of HPK1 is desirable to investigate the role of HPK1 in human immune cells with therapeutic implications. However, a significant challenge remains to identify a small molecule inhibitor of HPK1 with sufficient potency, selectivity, and other drug-like properties suitable for proof-of-concept studies. In this report, we identified a novel, potent, and selective HPK1 small molecule kinase inhibitor, compound K (CompK). A series of studies were conducted to investigate the mechanism of action of CompK, aiming to understand its potential application in cancer immunotherapy. METHODS: Human primary T cells and dendritic cells (DCs) were investigated with CompK treatment under conditions relevant to tumor microenvironment (TME). Syngeneic tumor models were used to assess the in vivo pharmacology of CompK followed by human tumor interrogation ex vivo. RESULTS: CompK treatment demonstrated markedly enhanced human T-cell immune responses under immunosuppressive conditions relevant to the TME and an increased avidity of the T-cell receptor (TCR) to recognize viral and tumor-associated antigens (TAAs) in significant synergy with anti-PD1. Animal model studies, including 1956 sarcoma and MC38 syngeneic models, revealed improved immune responses and superb antitumor efficacy in combination of CompK with anti-PD-1. An elevated immune response induced by CompK was observed with fresh tumor samples from multiple patients with colorectal carcinoma, suggesting a mechanistic translation from mouse model to human disease. CONCLUSION: CompK treatment significantly improved human T-cell functions, with enhanced TCR avidity to recognize TAAs and tumor cytolytic activity by CD8+ T cells. Additional benefits include DC maturation and priming facilitation in tumor draining lymph node. CompK represents a novel pharmacological agent to address cancer treatment resistance.
Subject(s)
Antineoplastic Agents/administration & dosage , Bone Neoplasms/drug therapy , Ginsenosides/administration & dosage , Protein Serine-Threonine Kinases/antagonists & inhibitors , Sarcoma/drug therapy , Animals , Antineoplastic Agents/pharmacology , Bone Neoplasms/immunology , Bone Neoplasms/metabolism , Cell Line , Cell Proliferation/drug effects , Cell Survival/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Ginsenosides/pharmacology , Humans , Mice , Receptors, Antigen, T-Cell/metabolism , Sarcoma/immunology , Sarcoma/metabolism , Treatment Outcome , Tumor Microenvironment/drug effects , Xenograft Model Antitumor AssaysABSTRACT
High-affinity, functionally potent, urea-based antagonists of CCR1 have been discovered. Modulation of PXR transactivation has revealed the selective and orally bioavailable CCR1 antagonist BMS-817399 (29), which entered clinical trials for the treatment of rheumatoid arthritis.
Subject(s)
Arthritis, Rheumatoid/drug therapy , Drug Discovery , Piperidines/pharmacology , Receptors, CCR1/antagonists & inhibitors , Urea/analogs & derivatives , Valine/analogs & derivatives , Animals , Biological Availability , Clinical Trials, Phase II as Topic , Hep G2 Cells , Humans , Male , Microsomes, Liver/metabolism , Models, Molecular , Piperidines/metabolism , Piperidines/pharmacokinetics , Piperidines/therapeutic use , Pregnane X Receptor , Protein Conformation , Receptors, CCR1/chemistry , Receptors, CCR1/metabolism , Receptors, Steroid/metabolism , Species Specificity , Urea/metabolism , Urea/pharmacokinetics , Urea/pharmacology , Urea/therapeutic use , Valine/metabolism , Valine/pharmacokinetics , Valine/pharmacology , Valine/therapeutic useABSTRACT
A series of compounds which exhibited good human CCR1 binding and functional potency was modified resulting in the discovery of a novel series of high affinity, functionally potent antagonists of the CCR1 receptor. Issues of PXR activity, ion-channel potency, and poor metabolic stability were addressed by the addition of a hydroxyl group to an otherwise lipophilic area in the molecule resulting in the discovery of preclinical candidate BMS-457 for the treatment of rheumatoid arthritis.
Subject(s)
Drug Discovery , Piperidines/pharmacology , Receptors, CCR1/antagonists & inhibitors , Dose-Response Relationship, Drug , Humans , Molecular Structure , Piperidines/chemical synthesis , Piperidines/chemistry , Structure-Activity RelationshipABSTRACT
A series of novel, potent CCR1 inhibitors was developed from a moderately active hit using an iterative parallel synthesis approach. The initial hit (composed of three subunits: an amine, a central amino acid, and an N-terminal cap) became the basis for a series of parallel chemical libraries designed to generate SAR data. Libraries were synthesized that explored each of the three subunits; the CCR1 binding data obtained revealed the following: (1) changes to the amine are not well tolerated; (2) small alkylamino acids are preferred in the center of the molecule; (3) substitutions at the N-terminus are generally well tolerated. These data were used to drive the optimization of the series, ultimately providing a lead with a CCR1 binding IC(50) of 28 nM (48). This lead demonstrates high selectivity for CCR1 over other CCR-family members, high microsomal stability, and good pharmacokinetics in mice.
